Mower with motor cooling

ABSTRACT

A mower includes a rotary blade cutting grass due to being rotationally driven. A work motor rotationally drives the rotary blade. A mower deck houses the rotary blade in an interior thereof. A first shroud forms an air flow passage along the work motor. The air flow passage connects the interior and exterior of the mower deck.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119 of JapaneseApplication No. 2014-123822, filed on Jun. 16, 2014, the disclosure ofwhich is expressly incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mower technology that includes amotor rotationally driving a rotary blade.

2. Description of Related Art

Conventionally, a mower technology that includes a motor rotationallydriving a rotary blade is well known, such as that described in JapanesePatent Laid-open Publication No. 2013-021921.

Japanese Patent Laid-open Publication No. 2013-021921 describes a mower(mower deck unit) that includes a mower deck housing a rotary blade(mower blade) in an interior thereof; and a motor (mower motor)rotationally driving the rotary blade. The motor is fixated on a topsurface of the mower deck by bolts. In the mower configured in this way,grass (a lawn) can be mowed by driving the motor and rotationallydriving the rotary blade.

In the mower configured in this way, when the rotary blade isrotationally driven, heat is produced by the motor. Therefore, a mowercapable of effectively cooling a hot motor is preferred.

SUMMARY OF THE INVENTION

In view of the above-noted circumstances, the present invention providesa mower capable of effectively cooling a motor.

Specifically, a mower according to one aspect of the present inventionincludes a rotary blade cutting grass due to being rotationally driven;a motor rotationally driving the rotary blade; a mower deck housing therotary blade in an interior thereof; and a guide member forming an airflow passage along the motor, the air flow passage connecting theinterior and exterior of the mower deck.

According to another aspect of the present invention, the guide memberis positioned so as to face a side surface of the motor.

According to another aspect of the present invention, the motor includesat least one fin, which is formed so as to extend outward from the sidesurface, and such that an outer edge portion of the fin touches theguide member.

According to another aspect of the present invention, the mower furtherincludes a fan, which sends air from the exterior of the mower deck tothe interior via the air flow passage.

According to another aspect of the present invention, the fan is drivenby the motor.

Effects of the present invention are as follows.

The motor can be cooled effectively by air flowing from the exterior ofthe mower deck to the interior (or from the interior to the exterior).

The side surface of the motor can be cooled effectively.

A surface area of the motor can be increased, and the motor can becooled effectively. In addition, heat can be dissipated via the fin andthe guide member, and the motor can be cooled more effectively.

An amount of airflow can be increased, and the motor can be cooled moreeffectively.

There is no need to provide a separate drive source driving the fan.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed descriptionwhich follows, in reference to the noted plurality of drawings by way ofnon-limiting examples of exemplary embodiments of the present invention,in which like reference numerals represent similar parts throughout theseveral views of the drawings, and wherein:

FIG. 1 is a lateral view illustrating an overall configuration of a lawnmower;

FIG. 2 is a plan or top view of the same;

FIG. 3 is an overhead exploded perspective view of a top portion of amower according to a first embodiment;

FIG. 4 is an overhead exploded perspective view of a bottom portion ofthe mower;

FIG. 5 is an underside exploded perspective view of the top portion ofthe mower;

FIG. 6 is an underside exploded perspective view of the bottom portionof the mower;

FIG. 7 is an enlarged plan view of the mower;

FIG. 8 is a cross-sectional view along a line A-A in FIG. 7;

FIG. 9 is a cross-sectional view along the line A-A illustrating how airflows;

FIG. 10 is an overhead exploded perspective view of a top portion of amower according to a second embodiment;

FIG. 11 is an overhead exploded perspective view of a bottom portion ofthe mower;

FIG. 12 is an underside exploded perspective view of the top portion ofthe mower;

FIG. 13 is an underside exploded perspective view of the bottom portionof the mower;

FIG. 14 is an enlarged plan view of the mower;

FIG. 15 is a cross-sectional view along a line B-B in FIG. 14;

FIG. 16 is a cross-sectional view along a line C-C in FIG. 14;

FIG. 17 is a cross-sectional view along the line B-B illustrating howair flows;

FIG. 18 is a cross-sectional view illustrating a mower according to afirst modification;

FIG. 19 is a cross-sectional view illustrating a mower according to asecond modification;

FIG. 20 is an overhead perspective view of a fan and a scraper accordingto the second modification;

FIG. 21A is an enlarged cross-sectional view of a mower according to athird modification in a state where a temperature of a work motor islow; FIG. 21B is an enlarged cross-sectional view of the mower in astate where the temperature of the work motor is high; and

FIG. 22 is a lateral view illustrating another configuration of a lawnmower.

DETAILED DESCRIPTION OF THE INVENTION

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the embodiments of the present invention onlyand are presented in the cause of providing what is believed to be themost useful and readily understood description of the principles andconceptual aspects of the present invention. In this regard, no attemptis made to show structural details of the present invention in moredetail than is necessary for the fundamental understanding of thepresent invention, the description taken with the drawings makingapparent to those skilled in the art how the forms of the presentinvention may be embodied in practice.

In the following, directions indicated in the drawings by arrows U, D,F, B, L, and R shall be defined in the description as an upwarddirection, a downward direction, a forward (front) direction, a rearward(back) direction, a left direction, and a right direction, respectively.

First, with reference to FIGS. 1 and 2, an overall configuration of alawn mower 1 equipped with a mower 100 is described.

The lawn mower 1 is a work vehicle capable of mowing grass (a lawn)while traveling. The lawn mower 1 includes primarily a traveling vehiclebody 2, front wheels 3, drive wheels 4, a travel motor 5, a driver'sseat 6, a protective frame 7, a travel lever(s) 8, a link mechanism 9,and the mower 100.

A front portion of the traveling vehicle body 2 is supported by aleft-right pair of the front wheels 3, which are coupled wheels(non-drive wheels). A rear portion of the traveling vehicle body 2 issupported by a left-right pair of the drive wheels 4. A left-right pairof the travel motors 5 are provided in respective interiors of theleft-right pair of drive wheels 4. The left travel motor 5 is coupled tothe left drive wheel 4, and the right travel motor 5 is coupled to theright drive wheel 4.

The driver's seat 6, where a worker or operator sits, is provided at afront-back direction middle portion of the traveling vehicle body 2. Theprotective frame 7, which protects the worker, is provided to the rearof the driver's seat 6. A left-right pair of the travel levers 8 areprovided to the left and right of the driver's seat 6. The mower 100 islocated at a bottom portion of the traveling vehicle body 2 (between thefront wheels 3 and the drive wheels 4) and supported via the linkmechanism 9.

The worker can control driving revolutions of each of the left-rightpair of travel motors 5 by operating the respective travel lever 8.Thereby, the worker can independently drive each of the left-right pairof the drive wheels 4 as desired. In this way, the lawn mower 1 can bemade to advance forward and rearward or to turn due to the workeroperating the travel levers 8. In addition, by driving the mower 100,the worker can perform mowing work (grass-cutting work).

Next, with reference to FIGS. 3 to 9, a configuration of the mower 100(and in particular, a configuration related to a work motor 120described hereafter) according to a first embodiment of the presentinvention is described.

The mower 100 is a work apparatus that cuts grass growing below themower 100 such that the grass is a predetermined length (height). Themower 100 includes primarily a mower deck 110, a work motor 120, aspacer 130, a fan 140, a rotary blade 150, a first shroud 160, and asecond shroud 170.

For ease of description in the following, only a configuration in avicinity of a left end portion of the mower 100 is described. Morespecifically, the mower 100 according to the present embodiment includesa plurality of (e.g., three) work motors 120 (see FIG. 2); however, inthe following, only the configuration of the work motor 120 in theleft-most position and an area around this work motor 120 are described.

The mower deck 110 shown in FIGS. 3 to 8 forms a principal structure ofthe mower 100. The mower deck 110 includes primarily a top surface 111and a side surface 112.

The top surface 111 is a plate-shaped portion formed so as to besubstantially horizontal. The top surface 111 is formed such that alength direction thereof is oriented along the left-right direction. Theside surface 112 is a portion formed so as to extend downward from anouter peripheral end of the top surface 111. The top surface 111 and theside surface 112 can be integrally formed. A connection portion betweenthe top surface 111 and the side surface 112 is formed so as to create asmoothly curved surface. A space covered from above and laterally isformed in an interior of the mower deck 110 by the top surface 111 andthe side surface 112. Primarily, a center hole 111 a and a communicatinghole(s) 111 b are formed on the top surface 111.

The center hole 111 a is formed so as to run through the top surface 111vertically. The center hole 111 a is formed to have a round shape in aplan or top view.

The communicating hole(s) 111 b is formed so as to run through the topsurface 111 vertically. A plurality of the communicating holes 111 b(eight in the present embodiment) are formed around a periphery of thecenter hole 111 a. The communicating holes 111 b are formed at equalintervals along a circumference centered on the center hole 111 a.

The work motor 120 shown in FIGS. 3, 5, 7, and 8 rotationally drives therotary blade 150 (described below) using electric power. The work motor120 includes primarily a housing 121, a shaft 122, a rotor 123, and astator 124.

The housing 121 forms a principal structure of the work motor 120. Thehousing 121 includes primarily a main body 121 a, a top portion 121 b,and a bottom portion 121 c.

The main body 121 a is formed in a substantially cylindrical shapehaving an axis line oriented in the vertical direction. A diameter ofthe main body 121 a is formed so as to be smaller than a diameter of acircumference formed by the communicating holes 111 b of the mower deck110.

The top portion 121 b and bottom portion 121 c are formed in asubstantially cylindrical shape having an axis line oriented in thevertical direction. The top portion 121 b is integrally formed with atop surface of the main body 121 a. The bottom portion 121 c isintegrally formed with a bottom surface of the main body 121 a. The topportion 121 b and bottom portion 121 c are formed on the axis line ofthe main body 121 a. The diameter of the bottom portion 121 c is formedso as to be substantially identical to the diameter of the center hole111 a of the mower deck 110.

In an interior of the housing 121, which is a casing member formed inthe above way, a space is formed where various components are placed.Fins 121 d are formed on the housing 121.

The fins 121 d are formed in substantially a rectangular plate shape,and are formed so as to span from a top edge to a bottom edge of themain body 121 a. A plurality of the fins 121 d (eight in the presentembodiment) are formed on the side surface of the main body 121 a. Thefins 121 d are formed so as to extend radially outward from the sidesurface of the main body 121 a. A surface area of the housing 121 can beincreased by the formation of the fins 121 d.

The shaft 122 shown in FIGS. 5 and 8 outputs rotational drive power ofthe work motor 120. The shaft 122 is positioned in the center (on theaxis line) of the housing 121 in a state where the axis line is orientedin the vertical direction. A bottom end of the shaft 122 is positionedso as to project downward from the bottom surface of the housing 121.The shaft 122 is supported so as to be capable of rotation by atop-bottom pair of bearings 122 a provided in the interior of thehousing 121.

The rotor 123 shown in FIG. 8 is a field magnet (or an armature) capableof rotating together with the shaft 122. The rotor 123 is positionedwithin the housing 121. The rotor 123 is fixated to a vertical directionmiddle portion of the shaft 122 and can rotate together with the shaft122.

The stator 124 is an armature (or a field magnet) fixated within thehousing 121. The stator 124 is positioned within the housing 121 so asto laterally surround the rotor 123.

The work motor 120 configured in this way is placed on the top surface111 of the mower deck 110. The work motor 120 is positioned such thatthe axis line of the work motor 120 matches the center of the centerhole 111 a of the mower deck 110. In this case, the bottom portion 121 cof the housing 121 is inserted through the center hole 111 a of themower deck 110. Accordingly, the bottom end of the bottom portion 121 cis positioned in an interior of the mower deck 110 (lower than the topsurface 111 of the mower deck 110). The bottom end of the shaft 122 ofthe work motor 120 projects toward the interior of the mower deck 110via the center hole 111 a. In such a work motor 120, electric currentflows to and excites the stator 124 (or the rotor 123), thereby causingthe rotor to rotate and enabling the shaft 122 to be rotated androtational drive power to be obtained.

The spacer 130 shown in FIGS. 4, 6, and 8 transmits the rotational drivepower being output from the shaft 122 of the work motor 120 even furtherdownward than the shaft 122. The spacer 130 includes primarily a housing131, a flange 132, a shaft coupling 133, and a seal member 134.

The housing 131 forms a principal structure of the spacer 130. Thehousing 131 is formed in a substantially cylindrical shape having anaxis line oriented in the vertical direction.

The flange 132 is a substantially rectangular plate-shaped portion. Theflange 132 is positioned so as to be substantially horizontal. Theflange 132 is fixed or connected to the top end of the housing 131.

The shaft coupling 133 transmits the rotational drive power from theshaft 122 of the work motor 120. The shaft coupling 133 is formed in asubstantially cylindrical shape having an axis line oriented in thevertical direction. The shaft coupling 133 is positioned in the center(on the axis line) of the housing 131. The shaft coupling 133 issupported so as to be capable of rotation by a top-bottom pair ofbearings 133 a provided in the interior of the housing 131.

The seal member 134 seals the bottom end of the housing 131 asappropriate. By sealing the bottom end of the housing 131 with the sealmember 134, foreign objects can be prevented from infiltrating thehousing 131.

The spacer 130 configured in this way is placed in the interior of themower deck 110. The spacer 130 is positioned such that the axis line ofthe spacer 130 (axis line of the shaft coupling 133) matches the centerof the center hole 111 a of the mower deck 110. In this state, theflange 132 of the spacer 130 is fixated to the top surface 111 of themower deck 110 as appropriate using bolts or the like. In this case, thebottom end of the shaft 122 of the work motor 120 is coupled to the topend of the shaft coupling 133 of the spacer 130 such that the shaft 122is not capable of relative rotation. Thereby, the shaft coupling 133 canbe rotated together with the shaft 122.

The fan 140 (centrifugal fan) sends (circulates) air from an interior tothe exterior. The fan 140 includes primarily a top plate 141, a bottomplate 142, and fan blades 143.

The top plate 141 is formed in substantially a circular plate shape. Thetop plate 141 is positioned so as to be substantially horizontal. Acenter hole 141 a is formed on the top plate 141.

A center hole 141 a is formed so as to run through the top plate 141vertically. The center hole 141 a is formed to have a circular shape ina plan view. The center hole 141 a is formed at a center of the topplate 141.

The bottom plate 142 is formed in substantially a circular plate shape.A diameter of the bottom plate 142 is formed so as to be smaller than adiameter of the top plate 141. The bottom plate 142 is positioned so asto be parallel with the top plate 141 (substantially horizontal). Thebottom plate 142 is positioned below the top plate 141 in a stateseparated from the top plate 141 by a predetermined distance. The bottomplate 142 is positioned such that an axis line of the bottom plate 142matches the axis line of the top plate 141. A center hole 142 a and ribs142 b are formed on the bottom plate 142.

The center hole 142 a is formed so as to run through the bottom plate142 vertically. The center hole 142 a is formed to have a circular shapein a plan view. The center hole 142 a is formed at a center of thebottom plate 142. A diameter of the center hole 142 a of the bottomplate 142 is formed so as to be smaller than a diameter of the centerhole 141 a of the top plate 141.

The ribs 142 b are formed so as to project downward from the bottomsurface of the bottom plate 142. Two of the ribs 142 b are provided soas to have the center hole 142 a therebetween in a bottom view. The tworibs 142 b are formed so as to extend parallel to each other in a bottomview.

The fan blades 143 displace air (generate airflow) between the top plate141 and the bottom plate 142. The fan blades 143 are formed by bending asubstantially rectangular plate-shaped member as appropriate. The fanblades 143 are fixated to the top plate 141 and the bottom plate 142 soas to couple the top plate 141 and the bottom plate 142. A plurality ofthe fan blades 143 (eight in the present embodiment) are provided arounda periphery of the axis lines of the top plate 141 and the bottom plate142.

The fan 140 configured in this way is placed in the interior of themower deck 110. The fan 140 is positioned such that an axis line of thefan 140 matches the axis line of the spacer 130. In this state, the fan140 is coupled to the spacer 130 (shaft coupling 133) from below.Thereby, the fan 140 can be rotated together with the shaft coupling133. In this case, the bottom portion of the housing 131 of the spacer130 is inserted through the center hole 141 a of the top plate 141 ofthe fan 140. In addition, the bottom end of the spacer 130 (the sealmember 134) abuts the bottom plate 142 of the fan 140 (see FIG. 4).

The rotary blade 150 cuts grass due to being rotationally driven. Therotary blade 150 is formed in substantially a rectangular plate shape.The rotary blade 150 is bent as appropriate and, when rotated, can send(circulate) air upward from below. A through-hole 151 running throughthe rotary blade 150 vertically is provided at the center of the rotaryblade 150.

The rotary blade 150 configured in this way is placed in the interior ofthe mower deck 110. The rotary blade 150 is fitted, from below the fan140, between the two ribs 142 b formed on the fan 140. In this state, abolt 135 is fastened to the spacer 130 (shaft coupling 133) via a metalwasher 136 from below the rotary blade 150. In this way, the drive powerfrom the work motor 120 is transmitted to the fan 140 and the rotaryblade 150 via the shaft coupling 133. The fan 140 and the rotary blade150 rotate integrally or together.

The first shroud 160 shown in FIGS. 3, 5, 7, and 8 forms a path throughwhich air flows (an air flow passage). The first shroud 160 is formed ina substantially cylindrical shape having an axis line oriented in thevertical direction. An inner diameter of the first shroud 160 is formedso as to be larger than the diameter of the housing 121 of the workmotor 120. The inner diameter of the first shroud 160 is also formed soas to be larger than the diameter of the circumference formed by thecommunicating holes 111 b of the mower deck 110. A vertical directionbreadth (height) of the first shroud 160 is formed so as to besubstantially identical to the vertical direction breadth of the housing121 of the work motor 120. A fixation portion(s) 161 is formed on thefirst shroud 160.

The fixation portion(s) 161 is formed in substantially a rectangularplate shape. A plurality of the fixation portions 161 (three in thepresent embodiment) are formed on a bottom edge of the first shroud 160.The fixation portions 161 are formed so as to extend outward from thebottom edge of the first shroud 160. The fixation portions 161 areformed so as to be substantially horizontal.

The first shroud 160 configured in this way is placed on the top surface111 such that the fixation portions 161 make contact with the topsurface 111 of the mower deck 110. The first shroud 160 is positionedsuch that an axis line of the first shroud 160 matches the axis line ofthe work motor 120. Thereby, the first shroud 160 is positioned in astate leaving a predetermined gap open between the first shroud 160 andthe side surface of the work motor 120. Specifically, a substantiallycylindrical space is formed between the first shroud 160 and the workmotor 120. In this case, an outer edge portion of the fins 121 d of thework motor 120 is positioned so as to touch an inner surface of thefirst shroud 160.

The second shroud 170 shown in FIGS. 4, 6, 7, and 8 forms an air flowpassage. The second shroud 170 is formed in a substantially cylindricalshape having an axis line oriented in the vertical direction. An innerdiameter of the second shroud 170 is formed so as to be larger than theinner diameter of the first shroud 160. An outer diameter of the secondshroud 170 is formed so as to be substantially identical to the diameterof the top plate 141 of the fan 140. A vertical direction breadth of thesecond shroud 170 is formed so as to be substantially identical to adistance between the top surface 111 of the mower deck 110 and the topplate 141 of the fan 140. A fixation portion 171 is provided on thesecond shroud 170.

The fixation portion(s) 171 is formed in a substantially cylindricalshape having an axis line oriented in the vertical direction. Aplurality of the fixation portions 171 (three in the present embodiment)are formed on a top edge of an outer surface of the second shroud 170.The fixation portions 171 are each provided in positions overlappingwith the fixation portions 161 of the first shroud 160 in a plan view.The fixation portions 171 are positioned so as to project upward fromthe top edge of the second shroud 170. A male threaded portion (notpictured) is formed on a top end of the fixation portions 171.

The second shroud 170 configured in this way is placed in the interiorof the mower deck 110. The second shroud 170 is positioned such that anaxis line of the second shroud 170 matches the axis line of the spacer130. In this state, the second shroud 170 abuts the top surface 111 ofthe mower deck 110 from below. In this case, the top ends of thefixation portions 171 of the second shroud 170 are inserted through thetop surface 111 of the mower deck 110 and through the respectivefixation portions 161 of the first shroud 160. A nut 172 is fastenedonto the fixation portions 171 from above the fixation portions 161 ofthe first shroud 160. Thereby, the first shroud 160 and the secondshroud 170 are fixated to the mower deck 110. Moreover, after the secondshroud 170 is fixated to the mower deck 110, the fan 140 and the rotaryblade 150 are fixated to the spacer 130.

In the mower 100 configured in this way, an air flow passage is formedthat connects the interior of the mower deck 110 with the exterior.Hereafter, a manner in which the air flows through the air flow passageis described.

When the work motor 120 is driven, the fan 140 and rotary blade 150 arerotationally driven by the rotational drive power of the work motor 120.Due to the fan 140 and the rotary blade 150 rotating, air flows from theexterior of the mower deck 110 to the interior.

Specifically, as shown in FIG. 9, the air outside the mower deck 110(above the mower deck 110) flows from above downward through the spacebetween the first shroud 160 and the side surface of the housing 121 ofthe work motor 120. In this case, the work motor 120 (side surface ofthe housing 121) is cooled by the air flowing alongside the work motor120. In addition, the fins 121 d (see FIG. 7) are formed on the sidesurface of the housing 121, and therefore the surface area of thehousing 121 is increased as compared to a case where the fins 121 d arenot formed. Therefore, the housing 121 can be cooled effectively by theflowing air. The fins 121 d are also in contact with the first shroud160. Therefore, heat of the work motor 120 can be dissipated to theexterior of the mower deck 110 via the fins 121 d and the first shroud160, and the work motor 120 can be cooled effectively.

The air flowing downward through the space between the side surface ofthe housing 121 and the first shroud 160 flows into the interior of themower deck 110 via the communicating holes 111 b of the mower deck 110.The air flows toward the interior (in a direction approaching the axisline of the work motor 120) through the space demarcated by the topsurface 111 of the mower deck 110, the second shroud 170, and the topplate 141 of the fan 140. In this case, the air flowing alongside themower deck 110 cools the work motor 120 (bottom surface of the housing121) via the top surface 111 of the mower deck 110. In particular, inthe present embodiment, a portion of the work motor 120 (bottom end ofthe bottom portion 121 c of the housing 121) is positioned in theinterior of the mower deck 110. Accordingly, the work motor 120 can becooled effectively by the airflow in the interior of the mower deck 110.

The air flowing toward the interior through the space demarcated by thetop surface 111, the second shroud 170, and the top plate 141 flows intothe space between the top plate 141 and the bottom plate 142 via thecenter hole 141 a of the top plate 141. The air is sent outward by thefan blades 143 of the rotating fan 140.

In this way, in the mower 100, the air flow passage is formed along theside surface and bottom surface of the work motor 120. Therefore, thework motor 120 can be cooled effectively. In addition, the work motor120 can be cooled using air from the exterior of the mower deck 110,which contains fewer foreign bodies (mowed grass (turf), dust particles,and so on) as compared to the air in the interior of the mower deck 110.Therefore, foreign bodies are unlikely to get stuck in the air flowpassage, and a reduction in cooling performance can be inhibited.

As noted above, the mower 100 according to the present embodimentincludes the rotary blade 150 cutting grass due to being rotationallydriven; the work motor 120 (motor) rotationally driving the rotary blade150; the mower deck 110 housing the rotary blade 150 in the interiorthereof; and the first shroud 160 (guide member) forming the air flowpassage along the work motor 120, the air flow passage connecting theinterior and exterior of the mower deck 110. Due to this configuration,the work motor 120 can be cooled effectively by air flowing from theexterior of the mower deck 110 to the interior. Accordingly, a reductionin output of the work motor 120 can be inhibited.

In addition, the first shroud 160 is positioned so as to face the sidesurface of the work motor 120. Due to this configuration, the sidesurface of the work motor 120 can be cooled effectively.

The work motor 120 includes at least one fin 121 d, which is formed soas to extend outward from the side surface, and such that the outer edgeportion touches the first shroud 160. Due to this configuration, thesurface area of the work motor 120 can be increased, and the work motor120 can be cooled effectively. In addition, heat can be dissipated viathe fin 121 d and the first shroud 160, and the work motor 120 can becooled more effectively. Also, due to the fin 121 d touching the firstshroud 160, deformation of or damage to the first shroud 160 can beinhibited.

In addition, the mower 100 further includes the fan 140, which sends airfrom the exterior to the interior of the mower deck 110. Due to thisconfiguration, an amount of airflow can be increased, and the work motor120 can be cooled more effectively.

The fan 140 is also driven by the work motor 120. Due to thisconfiguration, there is no need to provide a separate drive sourcedriving the fan 140.

The mower 100 according to the present embodiment is an embodiment of amower according to the present invention, and various concreteconfigurations can be altered as desired within the technical scope ofthe present invention.

A number of work motors 120 provided to the mower 100 is notparticularly limited. In addition, a configuration is also possible inwhich a plurality of rotary blades 150 are rotationally driven by asingle work motor 120.

A number of fins 121 d is not particularly limited. By increasing thenumber of fins 121 d, the surface area of the work motor 120 (housing121) can be increased.

A configuration is also possible in which the fan 140 is not provided tothe mower 100. In this case, air can be caused to flow accompanying therotation of the rotary blade 150.

Furthermore, the fan 140 is not limited to being positioned below thework motor 120, but can be placed in any desired position. For example,a configuration is possible in which the fan 140 is positioned above thework motor 120 and air is sent downward (toward the interior of themower deck 110).

Next, with reference to FIGS. 10 to 17, a configuration of a mower 200(and in particular, a configuration related to a work motor 220described hereafter) according to a second embodiment of the presentinvention is described.

The mower 200 is a work apparatus that cuts grass growing below themower 200 such that the grass is a predetermined length (height). Themower 200 includes primarily a mower deck 210, the work motor 220, amotor cover 230, a fan 240, a rotary blade 250, and a shroud 260.

For ease of description in the following, only a configuration in avicinity of a left end portion of the mower 200 is described. Morespecifically, the mower 200 according to the present embodiment includesa plurality of work motors 220; however, in the following, only theconfiguration of the work motor 220 in the left-most position and anarea around this work motor 220 are described.

The mower deck 210 shown in FIGS. 10 to 15 forms a principal structureof the mower 200. The mower deck 210 includes primarily a top surface211 and a side surface 212.

The top surface 211 is a plate-shaped portion formed so as to besubstantially horizontal. The top surface 211 is formed such that alength direction thereof is oriented along the left-right direction. Theside surface 212 is a portion formed so as to extend downward from anouter peripheral end of the top surface 211. The top surface 211 and theside surface 212 are integrally formed. A connection portion between thetop surface 211 and the side surface 212 is formed so as to create asmoothly curved surface. A space covered from above and laterally isformed in an interior of the mower deck 210 by the top surface 211 andthe side surface 212. Primarily, a center hole 211 a is formed on thetop surface 211.

The center hole 211 a is formed so as to run through the top surface 211vertically. The center hole 211 a is formed to have a round shape in aplan view.

The work motor 220 shown in FIGS. 10, 12, 14, 15, and 16 rotationallydrives the rotary blade 250 (described below) using electric power. Thework motor 220 includes primarily a lower housing 221, an upper housing222, a shaft 223, a rotor 224, a stator 225, and a seal member 226.

The lower housing 221 forms a principal structure of the work motor 220.The lower housing 221 includes a side surface having a substantiallycylindrical shape with an axis line oriented in the vertical direction,and a bottom surface having a substantially circular plate shapecovering a bottom portion of the side surface. A diameter of the lowerhousing 221 is formed so as to be smaller than a diameter of the centerhole 211 a of the mower deck 210. A through-hole having a bolt 227inserted therein (described hereafter) is formed on a bottom end portion(center of the bottom surface) of the lower housing 221. A first fin 221a and a second fin 221 b are formed on the lower housing 221.

The first fin 221 a and the second fin 221 b are formed in substantiallya rectangular plate shape, and are formed so as to span from a top edgeto a bottom edge of the lower housing 221. A plurality of the first fins221 a and the second fins 221 b (four each in the present embodiment)are formed on the side surface of the lower housing 221. The first fins221 a and the second fins 221 b are provided so as to alternate in acircumference direction of the side surface of the lower housing 221.The first fins 221 a and the second fins 221 b are formed so as toextend radially outward from the side surface of the lower housing 221.A length from an inner edge to an outer edge of the first fins 221 a andthe second fins 221 b is formed to be identical for all fins. Athickness of the top end portion of the first fins 221 a and the secondfins 221 b is formed so as to be thicker than other portions (the bottomportion). A female threaded portion 221 c is formed on the top end (topsurface) of the first fins 221 a (see FIG. 15). A female threadedportion 221 d is formed near the top end of the outer surface of thesecond fins 221 b (see FIG. 16). A surface area of the lower housing 221can be increased by the formation of the first fins 221 a and the secondfins 221 b.

The upper housing 222 covers the top portion of the lower housing 221.The upper housing 222 is formed in substantially a circular plate shape.A diameter of the upper housing 222 is formed so as to be substantiallyidentical to the diameter of the lower housing 221. A projection 222 ais formed on the upper housing 222.

The projection 222 a is a portion formed so as to project outward froman outer peripheral end of the upper housing 222. A plurality of theprojections 222 a (four in the present embodiment) are formed on theupper housing 222. The projections 222 a are formed so as to bepositioned at mutually equal intervals on an outer periphery of theupper housing 222. A first through-hole 222 b and a second through-hole222 c are formed on the projections 222 a.

The first through-hole 222 b and the second through-hole 222 c areformed so as to run through the upper housing 222 (projections 222 a)vertically. The first through-hole 222 b is formed near an inner edgeportion of the projections 222 a. The second through-hole 222 c isformed near an outer edge portion of the projections 222 a.

The upper housing 222 is placed over the lower housing 221 so as tocover the top portion of the lower housing 221. In this case, the firstthrough-hole 222 b of the upper housing 222 and the female threadedportion 221 c of the lower housing 221 are opposite each other. In thisstate, by fastening a bolt (not shown in the drawings) in the femalethreaded portion 221 c from above via the first through-hole 222 b, theupper housing 222 is fixated to the lower housing 221. In this way, inan interior of the casing member (housing) formed by the lower housing221 and the upper housing 222, a space is formed where variouscomponents are placed.

The shaft 223 shown in FIG. 15 outputs the rotational drive power of thework motor 220. The shaft 223 is positioned in the center (on the axisline) of the lower housing 221 and the upper housing 222 in a statewhere the axis line is oriented in the vertical direction. The shaft 223is supported so as to be capable of rotation by a top-bottom pair ofbearings 223 a provided in the interior of the lower housing 221 and theupper housing 222.

The rotor 224 is a field magnet (or an armature) capable of rotatingtogether with the shaft 223. The rotor 224 is positioned within thelower housing 221 and the upper housing 222. The rotor 224 is fixated toa vertical direction middle portion of the shaft 223 and can rotatetogether with the shaft 223.

The stator 225 is an armature (or a field magnet) fixated within thelower housing 221 and the upper housing 222. The stator 225 ispositioned within the lower housing 221 and the upper housing 222 so asto laterally encircle the rotor 224.

The seal member 226 seals the through-holes on the bottom end of thelower housing 221 as appropriate. By sealing the through-holes on thebottom end of the lower housing 221 with the seal member 226, foreignobjects can be prevented from infiltrating the lower housing 221.

The work motor 220 configured in this way is inserted into the centerhole 211 a from above the mower deck 210. The work motor 220 ispositioned such that the axis line of the work motor 220 matches thecenter of the center hole 211 a. The projections 222 a of the upperhousing 222 are placed on the top surface 211 of the mower deck 210. Inthis state, a bolt or the like (not shown in the drawings) is fastenedto the second through-hole 222 c of the upper housing 222, and the upperhousing 222 is fixated to the top surface 211 of the mower deck 210. Inthis way, substantially the entire work motor 220 (specifically, thelower housing 221, the bottom portion of the shaft 223, the rotor 224,the stator 225, and the like) is placed in the interior of the mowerdeck 210 (below the top surface 211 of the mower deck 210). Thereby, thework motor 220 can be prevented from protruding upward from the upperportion of the mower deck 210. Accordingly, the work motor 220 can beprevented from interfering with other members, and efficient use can bemade of the space above the mower deck 210 (to position other members,for example). In such a work motor 220, electric current flows to andexcites the rotor 224 or the stator 225, thereby enabling the shaft 223to be rotated and rotational drive power to be obtained.

The motor cover 230 shown in FIGS. 10, 12, 14, and 15 covers the topportion of the work motor 220. The motor cover 230 is formed by bendingan outer peripheral end portion of a substantially circular plate-shapedmember, as seen in a plan view, downward. A diameter of the motor cover230 is formed so as to be greater than a length from an outer endportion of one of the projections 222 a of the upper housing 222 to anouter end portion of another of the projections 222 a formed at aposition opposite the first projection 222 a.

The motor cover 230 configured in this way is fixated onto the workmotor 220 (upper housing 222) from above the work motor 220. In thiscase, an appropriate gap is formed between the outer peripheral endportion of the motor cover 230 and the top surface 211 of the mower deck210. The work motor 220 is covered from above by the motor cover 230.

The fan 240 shown in FIGS. 11, 13, 14, and 15 is a centrifugal fansending (circulating) air from the interior to the exterior. The fan 240includes primarily a top plate 241, a bottom plate 242, and fan blades243.

The top plate 241 is formed in substantially a circular plate shape. Thetop plate 241 is positioned so as to be substantially horizontal. Acenter hole 241 a is formed on the top plate 241.

The center hole 241 a is formed so as to run through the top plate 241vertically. The center hole 241 a is formed to have a circular shape ina plan view. The center hole 241 a is formed at the center of the topplate 241.

The bottom plate 242 is formed in substantially a circular plate shape.A diameter of the bottom plate 242 is formed so as to be substantiallyidentical to a diameter of the top plate 241. The bottom plate 242 ispositioned so as to be parallel with the top plate 241 (substantiallyhorizontal). The bottom plate 242 is positioned below the top plate 241in a state separated from the top plate 241 by a predetermined distance.The bottom plate 242 is positioned such that an axis line of the bottomplate 242 matches the axis line of the top plate 241. A center hole 242a and ribs 242 b are formed on the bottom plate 242.

The center hole 242 a is formed so as to run through the bottom plate242 vertically. The center hole 242 a is formed to have a circular shapein a plan view. The center hole 242 a is formed at the center of thebottom plate 242. A diameter of the center hole 242 a of the bottomplate 242 is formed so as to be smaller than the diameter of the centerhole 241 a of the top plate 241.

The ribs 242 b are formed so as to project downward from the bottomsurface of the bottom plate 242. Two of the ribs 242 b are provided soas to have the center hole 242 a therebetween in a bottom view. The tworibs 242 b are formed so as to extend parallel to each other in a bottomview.

The fan blades 243 displace air (generate airflow) between the top plate241 and the bottom plate 242. The fan blades 243 are formed by bending asubstantially rectangular plate-shaped member as appropriate. The fanblades 243 are fixated to the top plate 241 and the bottom plate 242 soas to couple the top plate 241 and the bottom plate 242. A plurality ofthe fan blades 243 (eight in the present embodiment) are provided arounda periphery of the axis lines of the top plate 241 and the bottom plate242.

The fan 240 configured in this way is placed in the interior of themower deck 210. The fan 240 is positioned such that an axis line of thefan 240 matches the axis line of the work motor 220. In this state, thefan 240 is coupled to the work motor 220 (shaft 223) from below the workmotor 220. Thereby, the fan 240 can be rotated together with the shaft223. In this case, the bottom end portion of the work motor 220 isinserted through the center hole 241 a of the top plate 241 of the fan240. In addition, the bottom end of the work motor 220 (the seal member226) abuts the bottom plate 242 of the fan 240.

The rotary blade 250 cuts grass due to being rotationally driven. Therotary blade 250 is formed in substantially a rectangular plate shape.The rotary blade 250 is bent as appropriate and, when rotated, can send(circulate) air upward from below. A through-hole 251 running throughthe rotary blade 250 vertically is provided at the center of the rotaryblade 250.

The rotary blade 250 configured in this way is placed in the interior ofthe mower deck 210. The rotary blade 250 is fitted, from below the fan240, between the two ribs 242 b formed on the fan 240. In this state,the bolt 227 is fastened to the work motor 220 (shaft 223) via a metalwasher 228 from below the rotary blade 250. In this way, the drive powerfrom the work motor 220 is transmitted to the fan 240 and the rotaryblade 250. The fan 240 and the rotary blade 250 integrally rotate.

The shroud 260 shown in FIGS. 11, 13, 14, 15, and 16 forms an air flowpassage. The shroud 260 is formed in a substantially cylindrical shapehaving an axis line oriented in the vertical direction. The shroud 260is formed by assembling a first shroud section 261 and a second shroudsection 262, which are formed in a semicircular shape in a plan view. Aninner diameter of the shroud 260 is formed so as to be substantiallyidentical to the diameter of the center hole 211 a of the mower deck210. The inner diameter of the shroud 260 is formed so as to be smallerthan the diameter of the top plate 241 of the fan 240. A verticaldirection breadth (height) of the shroud 260 is formed so as to besmaller than the vertical direction breadth of the lower housing 221 ofthe work motor 220. A plurality of through-holes 260 a running throughthe shroud 260 are formed near a top end portion of the shroud 260(first shroud 261 and second shroud 262).

The shroud 260 configured in this way is placed in the interior of themower deck 210. The shroud 260 is positioned such that an axis line ofthe shroud 260 matches the axis line of the work motor 220. In thisstate, the shroud 260 abuts the top surface 211 of the mower deck 210from below. In this case, a bolt (not shown in the drawings) is fastenedto the female threaded portion 221 d of the lower housing 221 (see FIG.16) via the through-holes 260 a of the shroud 260. Accordingly, theshroud 260 is fixated to the lower housing 221 in a state where thefirst fins 221 a and the second fins 221 b of the lower housing 221touch the shroud 260.

In the mower 200 configured in this way, an air flow passage is formedthat connects the interior of the mower deck 210 with the exterior.Hereafter, a manner in which the air flows through the air flow passageis described.

When the work motor 220 is driven, the fan 240 and rotary blade 250 arerotationally driven by the rotational drive power of the work motor 220.Due to the fan 240 and the rotary blade 250 rotating, air flows from theexterior of the mower deck 210 to the interior.

Specifically, as shown in FIG. 17, air on the exterior of the mower deck210 (above the mower deck 210) flows into the motor cover 230 (below themotor cover 230) through gaps between the motor cover 230 and the topsurface 211 of the mower deck 210.

The air flowing into the motor cover 230 flows into the interior of themower deck 210 via the center hole 211 a of the mower deck 210. The airflows from above downward through the space between the shroud 260 andthe side surface of the lower housing 221 of the work motor 220. In thiscase, the work motor 220 (side surface of the lower housing 221) iscooled by the air flowing alongside the lower housing 221. In addition,the first fins 221 a and the second fins 221 b (see FIG. 16 and thelike) are formed on the side surface of the lower housing 221, andtherefore the surface area of the lower housing 221 is increased ascompared to a case where the first fins 221 a and the second fins 221 bare not formed. Therefore, the lower housing 221 can be cooledeffectively by the flowing air. Also, the first fins 221 a and thesecond fins 221 b touch the shroud 260. Therefore, the heat of the workmotor 220 can be dissipated to the interior of the mower deck 210 viathe first fins 221 a and the second fins 221 b, and also via the shroud260, enabling the work motor 220 to be cooled effectively.

In particular, in the present embodiment, substantially the entire workmotor 220 is positioned in the interior of the mower deck 210.Accordingly, the work motor 220 can be cooled effectively by the airflowin the interior of the mower deck 210. More specifically, not only isairflow generated in the interior of the mower deck 210 by the fan 240,but airflow is also generated accompanying rotation of the rotary blade250. This airflow flows through an area around the work motor 220(shroud 260), thereby cooling the work motor 220 via the shroud 260.

The air flowing downward through the space between the side surface ofthe lower housing 221 and the shroud 260 flows toward the interior (in adirection approaching the axis line of the work motor 220) through thespace between the bottom surface of the lower housing 221 and the topplate 241 of the fan 240. In this case, the flowing air cools the workmotor 220 (bottom surface of the lower housing 221).

The air flowing toward the interior through the space between the bottomsurface of the lower housing 221 and the top plate 241 flows into thespace between the top plate 241 and the bottom plate 242 via the centerhole 241 a of the top plate 241. The air is sent outward by the fanblades 243 of the rotating fan 240.

In this way, in the mower 200, the air flow passage is formed along theside surface and bottom surface of the work motor 220. Therefore, thework motor 220 can be cooled effectively. In addition, the work motor220 can be cooled using air from the exterior of the mower deck 210,which contains fewer foreign bodies (mowed grass (turf), dust particles,and so on) as compared to the air in the interior of the mower deck 210.Therefore, foreign bodies are unlikely to get stuck in the air flowpassage, and a reduction in cooling performance can be inhibited.

As noted above, the mower 200 according to the present embodimentincludes the rotary blade 250 cutting grass due to being rotationallydriven; the mower deck 210 housing the rotary blade 250 in the interiorthereof; and the work motor 220 (motor) of which at least a portion ispositioned in the interior of the mower deck 210, the work motor 220rotationally driving the rotary blade 250. Due to this configuration,the work motor 220 can be cooled effectively by the airflow generatedwithin the mower deck 210 accompanying rotation of the rotary blade 250.Accordingly, a reduction in output of the work motor 220 can beinhibited. By positioning at least a portion of the work motor 220 inthe interior of the mower deck 210, the work motor 220 can be preventedfrom interfering with members on a top portion of the mower deck 210(such as the link mechanism 9, which supports the mower 200). Inaddition, the space above the mower deck 210 can be used efficiently.

The work motor 220 includes a casing member (the lower housing 221 andthe upper housing 222) forming an interior space, and at least a portionof the casing member is positioned in the interior of the mower deck210. Due to this configuration, the casing member of the work motor 220can be cooled by air flowing within the mower deck 210.

The work motor 220 includes the rotor 224 and the stator 225, whichobtain the rotational drive power, and at least a portion of the rotor224 or at least a portion of the stator 225 is positioned in theinterior of the mower deck 210. Due to this configuration, the rotor 224or the stator 225 of the work motor 220 can be cooled by air flowingwithin the mower deck 210.

The work motor 220 includes the rotor 224 and the stator 225, whichobtain the rotational drive power, and at least a portion of the rotor224 and at least a portion of the stator 225 are positioned in theinterior of the mower deck 210. Due to this configuration, the rotor 224and the stator 225 of the work motor 220 can be cooled by air flowingwithin the mower deck 210.

The mower 200 further includes a guide member (the shroud 260 and thefan 240), which forms an air flow passage along the work motor 220, theair flow passage connecting the interior and exterior of the mower deck210. Due to this configuration, the work motor 220 can be cooledeffectively by air flowing from the exterior of the mower deck 210 tothe interior.

In addition, the guide member includes the shroud 260 (first guidemember), which is positioned so as to face the side surface of the workmotor 220. Due to this configuration, the side surface of the work motor220 can be cooled effectively.

The work motor 220 includes at least one fin (the first fin 221 a andthe second fin 221 b), which is formed so as to extend outward from theside surface, and such that an outer edge portion touches the shroud260. Due to this configuration, the surface area of the work motor 220can be increased, and the work motor 220 can be cooled effectively. Inaddition, heat can be dissipated via the fin and the shroud 260, and thework motor 220 can be cooled more effectively. Also, due to the firstfin 221 a and the second fin 221 b touching the shroud 260, deformationof or damage to the shroud 260 can be inhibited.

In addition, the guide member includes the top plate 241 of the fan 240(second guide member), which is positioned so as to face the bottomsurface of the work motor 220. Due to this configuration, the bottomsurface of the work motor 220 can be cooled effectively.

In addition, the mower 200 further includes the fan 240, which sends airfrom the exterior of the mower deck 210 to the interior via the air flowpassage. Due to this configuration, an amount of airflow can beincreased, and the work motor 220 can be cooled more effectively.

In addition, the mower 200 further includes the fan 240, which ispositioned below the work motor 220 and sends air from the exterior ofthe mower deck 210 to the interior via the air flow passage, the mower200 having the second guide member formed by the top plate 241 (topsurface) of the fan 240. Due to this configuration, the fan 240 and thesecond guide member can serve dual purposes.

Moreover, the fan 240 is driven by the work motor 220. Due to thisconfiguration, there is no need to provide a separate drive sourcedriving the fan 240.

The mower 200 according to the present embodiment is an embodiment of amower according to the present invention, and various concreteconfigurations can be altered as desired within the technical scope ofthe present invention.

A number of work motors 220 provided to the mower 200 is notparticularly limited. In addition, a configuration is also possible inwhich a plurality of rotary blades 250 are rotationally driven by asingle work motor 220.

A number of the first fins 221 a and second fins 221 b is notparticularly limited. By increasing the number of first fins 221 a andsecond fins 221 b, the surface area of the work motor 220 (lower housing221) can be increased.

A configuration is also possible in which the fan 240 is not provided tothe mower 200. In this case, air can be caused to flow accompanying therotation of the rotary blade 250.

Furthermore, the fan 240 is not limited to being positioned below thework motor 220, but can be placed in any desired position. For example,a configuration is possible in which the fan 240 is positioned above thework motor 220 and air is sent downward (toward the interior of themower deck 210).

In the present embodiment, substantially the entire work motor 220 ispositioned in the interior of the mower deck 210; however, the presentinvention is not limited to this. For example, only a portion of thelower housing 221 may be positioned in the interior of the mower deck210, or the lower housing 221 and the upper housing 222 (i.e., theentire work motor 220) may be positioned in the interior of the mowerdeck 210.

In the present embodiment, the rotor 224 and the stator 225 of the workmotor 220 are positioned in the interior of the mower deck 210; however,a configuration is also possible in which only a portion of the rotor224 and the stator 225 is positioned in the interior of the mower deck210. In addition, a configuration is also possible in which only one ofthe rotor 224 and the stator 225 is positioned in the interior of themower deck 210.

Hereafter, a modification of a mower according to the present inventionis described. The modification described below is a modification of themower 200 according to the second embodiment. Thus, identical referencenumerals are assigned to components having substantially identicalconfigurations to those of the mower 200 according to the secondembodiment, and descriptions thereof are omitted where appropriate.Moreover, the modification that follows is a modification of the mower200 according to the second embodiment; however, the mower 100 accordingto the first embodiment can also be modified in a similar way.

First, a mower 300 according to a first modification is described withreference to FIG. 18. The mower 300 primarily differs from the mower 200according to the second embodiment in that the mower 300 is capable ofcooling a controller 310, which controls the work motor 220, togetherwith the work motor 220. A specific description follows.

The controller 310 controls the work motor 220. The controller 310 isconfigured by a memory, a calculation processor, and the like. Programscontrolling the work motor 220 and various kinds of data are stored bythe controller 310. The controller 310 is formed in a substantiallycylindrical shape having an axis line oriented in the verticaldirection. The controller 310 is placed on a top portion of the workmotor 220.

The mower 300 includes an upper shroud 320 instead of the motor cover230 according to the second embodiment. The upper shroud 320 forms anair flow passage. The upper shroud 320 is formed in a substantiallycylindrical shape having an axis line oriented in the verticaldirection. An inner diameter of the upper shroud 320 is formed so as tobe larger than the diameter of the controller 310. A vertical directionbreadth of the upper shroud 320 is formed so as to be substantiallyidentical to the vertical direction breadth of the controller 310.

The upper shroud 320 configured in this way is placed on the top surface211 such that the upper shroud 320 makes contact with the top surface211 of the mower deck 210. The upper shroud 320 is positioned such thatthe axis line of the upper shroud 320 matches the axis line of the workmotor 220. Thereby, the upper shroud 320 is positioned in a stateleaving a predetermined gap open between the upper shroud 320 and theside surface of the controller 310.

In the mower 300 configured in this way, when the fan 240 and the rotaryblade 250 are rotationally driven, air on the exterior of the mower deck210 flows downward from above through a space between the upper shroud320 and the side surface of the controller 310. In this case, thecontroller 310 is cooled by the air flowing alongside the controller310. The air flows into the interior of the mower deck 210 and cools thework motor 220.

Next, a mower 400 according to a second modification is described withreference to FIGS. 19 and 20. The mower 400 primarily differs from themower 200 according to the second embodiment in that the mower 400includes a scraper 410 that removes foreign bodies clinging to the fan240. A specific description follows.

The scraper 410 is formed by bending a substantially rectangularplate-shaped member. Specifically, the scraper 410 is formed insubstantially a “U” shape in a side view by bending upward two endportions of a horizontally positioned plate-shaped member. Athrough-hole 411 is formed on a side surface in an interior of thescraper 410.

The scraper 410 is positioned on an interior of the center hole 241 a ofthe fan 240. A bolt (not shown in the drawings) is inserted through thethrough-hole 411 from the outer side, and the bolt is fastened to thelower housing 221, thereby fixating the scraper 410 to the work motor220. In this state, a bottom surface of the scraper 410 is positionedclose to but not touching the bottom plate 242 of the fan 240. An outerside surface of the scraper 410 is positioned close to but not touchingan edge of the center hole 241 a of the top plate 241.

In the mower 400 configured in this way, the fan 240 rotates relative tothe scraper 410. When the fan 240 rotates, foreign bodies (for example,mowed grass (turf)) clinging to the top surface of the bottom plate 242and the edge of the center hole 241 a are removed by the scraping of thescraper 410. Thereby, a reduction in air circulation performance of thefan 240 can be prevented.

Moreover, a method of fixating the scraper 410 is not limited to that ofthe present modification (fixation by a bolt).

Next, a mower 500 according to a third modification is described withreference to FIGS. 21A and 21B. The mower 500 primarily differs from themower 200 according to the second embodiment in that the air flowpassage is opened and closed using a thermostat 510. A specificdescription follows.

The thermostat 510 vertically displaces (changes a position of) themotor cover 230 in response to a temperature of the work motor 220. Thethermostat 510 is formed using a bimetal or the like. The thermostat 510extends to become vertically long when the temperature rises, andcontracts when the temperature drops. The thermostat 510 is positionedbetween the motor cover 230 and the upper housing 222 of the work motor220. The thermostat 510 is placed on the work motor 220, and can thusoperate in response to the temperature of the work motor 220.

In the mower 500 configured in this way, in a case where the temperatureof the work motor 220 is low, as shown in FIG. 21A, the thermostat 510contracts. In this case, the motor cover 230 displaces downward and anouter peripheral end portion of the motor cover 230 makes contact withthe top surface 211 of the mower deck 210. In this way, the air flowpassage is closed by the motor cover 230.

In this state, air outside the mower deck 210 cannot flow into theinterior of the motor cover 230. Accordingly, even when the fan 240rotates, air outside the mower deck 210 does not flow into the interiorof the mower deck 210. In this way, in a case where the temperature ofthe work motor 220 is low, there is little need to cool the work motor220, and therefore the flow of air into the interior of the mower deck210 is regulated. Accordingly, an amount of airflow of the fan 240 canbe restrained, and a workload of the work motor 220 can be reduced.

As shown in FIG. 21B, in a case where the temperature of the work motor220 becomes high, the thermostat 510 extends vertically in response tothe temperature of the work motor 220. In this case, the motor cover 230displaces upward and a gap is formed between an outer peripheral endportion of the motor cover 230 and the top surface 211 of the mower deck210. In this way, the air flow passage is opened by the upwarddisplacement of the motor cover 230.

In this state, air outside the mower deck 210 can flow into the interiorof the mower deck 210 via the gap between the outer peripheral endportion of the motor cover 230 and the top surface 211 of the mower deck210. Accordingly, the work motor 220 can be cooled by the air. Thethermostat 510 extends to become longer as the temperature of the workmotor 220 increases. Therefore, as the temperature of the work motor 220increases, air outside the mower deck 210 can more easily flow into theinterior of the mower deck 210 and the work motor 220 can be cooledeffectively.

Moreover, in the mower 500, the motor cover 230 is displaced verticallyand the air flow passage is opened and closed using the thermostat 510.However, the present modification is not limited to the thermostat 510,and a configuration is also possible in which the air flow passage opensand closes using another mechanism (for example, a temperature sensordetecting the temperature of the work motor 220, a vertically expandingand contracting actuator, or the like).

Moreover, a configuration of a lawn mower that includes the moweraccording to the present invention is not limited to the lawn mower 1described above (see FIGS. 1 and 2). Specifically, the mower accordingto the present invention is not limited to a riding type (where grasscutting work is performed by a worker riding the mower) or a non-ridingtype (where grass cutting work is performed without the worker ridingthe mower), but can also be applied to various lawn mowers havingdesired configurations. In addition, the mower according to the presentinvention can be applied to a lawn mower traveling due to electric power(an electric lawn mower) as well as to a lawn mower traveling due toengine power.

For example, as shown in FIG. 22, the mower (exemplified in FIG. 22 bythe mower 100) may also be applied to a lawn mower 10, in which theworker does not sit down but instead rides standing up. The lawn mower10 includes a traveling vehicle body 11, a motor section 12, drivewheels 13, a platform 14, coupled driving wheels 15, a handle 16, andthe mower 100.

The traveling vehicle body 11 is supported by a left-right pair of thedrive wheels 13. The motor section 12 driving the left-right pair ofdrive wheels 13 is provided to the traveling vehicle body 11. Theplatform 14 where the worker rides standing is connected to a rearportion of the traveling vehicle body 11. A left-right pair of thecoupled driving wheels 15 are provided to a rear portion of the platform14. The handle 16 is provided to a top portion of the traveling vehiclebody 11 so as to extend upward. The mower 100 is coupled to a frontportion of the traveling vehicle body 11.

In the lawn mower 10 configured in this way, the worker can stably ridethe mower 10 by gripping the handle 16 while mounted on the platform 14.The worker can independently drive each of the left-right pair of drivewheels 13 and can cause the lawn mower 10 to travel as desired byperforming a predetermined operation (for example, swinging the handle16 forward/rearward or left/right, displacing the center of gravity ofthe worker's body, and the like).

It is noted that the foregoing examples have been provided merely forthe purpose of explanation and are in no way to be construed as limitingof the present invention. While the present invention has been describedwith reference to exemplary embodiments, it is understood that the wordswhich have been used herein are words of description and illustration,rather than words of limitation. Changes may be made, within the purviewof the appended claims, as presently stated and as amended, withoutdeparting from the scope and spirit of the present invention in itsaspects. Although the present invention has been described herein withreference to particular structures, materials and embodiments, thepresent invention is not intended to be limited to the particularsdisclosed herein; rather, the present invention extends to allfunctionally equivalent structures, methods and uses, such as are withinthe scope of the appended claims.

The present invention is not limited to the above described embodiments,and various variations and modifications may be possible withoutdeparting from the scope of the present invention.

What is claimed is:
 1. A mower comprising: at least one rotationallydriven grass cutting blade; at least one motor configured to causerotation of the grass cutting blade; a mower deck housing the rotaryblade in an interior thereof; and at least one guide member defining anair flow passage along the motor, the air flow passage connecting theinterior and exterior of the mower deck.
 2. The mower according to claim1, wherein the guide member is positioned so as to face or surround aside surface of the motor.
 3. The mower according to claim 2, whereinthe motor includes at least one fin projecting out from the side surfaceand extending to a surface of the guide member.
 4. The mower accordingto claim 1, further comprising a fan configured to draw air from theexterior of the mower deck to the interior via the air flow passage. 5.The mower according to claim 4, wherein the fan is driven by the motor.6. The mower according to claim 5, wherein the fan is located betweenthe motor and the grass cutting blade.
 7. A mower comprising: at leastone rotationally driven grass cutting blade; at least one electric motorconfigured to cause rotation of the grass cutting blade; a mower deckhousing the rotary blade in an interior thereof; and at least one guidemember defining a cooling air flow passage for cooling the motor, theair flow passage allowing for an air flow between the interior andexterior of the mower deck.
 8. The mower according to claim 7, whereinthe guide member is positioned above and outside the mower deck.
 9. Themower according to claim 7, wherein the motor is positioned above andoutside the mower deck.
 10. The mower according to claim 9, furthercomprising a fan is driven by the motor.
 11. The mower according toclaim 10, wherein the fan is located between the motor and the grasscutting blade.
 12. The mower according to claim 11, wherein the guidemember comprises a first guide member positioned above and outside themower deck and a second guide member positioned inside the mower deck.13. The mower according to claim 7, wherein the motor at least partiallyextends within the interior of the mower deck.
 14. The mower accordingto claim 13, further comprising a fan driven by the motor.
 15. The moweraccording to claim 14, wherein the fan is located between the motor andthe grass cutting blade.
 16. The mower according to claim 15, whereinthe guide member comprises a first guide member positioned above andoutside the mower deck and a second guide member positioned inside themower deck.
 17. The mower according to claim 15, wherein the guidemember comprises a first guide member that is axially movable andpositioned above and outside the mower deck and a second guide memberpositioned inside the mower deck.
 18. A mower comprising: a mower deck;at least one rotationally driven grass cutting blade; at least oneelectric motor configured to cause rotation of the grass cutting bladeand being mounted to an upper wall of the mower deck; at least one guidemember defining an air flow passage outside the motor; and at least onefan configured to draw air from outside the mower deck, through the airflow passage so as to cool the motor, and into an interior of the mowerdeck.
 19. The mower according to claim 18, wherein the guide membercomprises a first guide member positioned above and outside the upperwall of the mower deck and a second guide member positioned inside themower deck.
 20. The mower according to claim 18, wherein a housing ofthe motor at least partially extends within the interior of the mowerdeck.